Quantum algorithm for simulating the dynamics of an open quantum system

Hefeng Wang, Sahel Ashhab, Franco Nori

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

In the study of open quantum systems, one typically obtains the decoherence dynamics by solving a master equation. The master equation is derived using knowledge of some basic properties of the system, the environment, and their interaction: One basically needs to know the operators through which the system couples to the environment and the spectral density of the environment. For a large system, it could become prohibitively difficult to even write down the appropriate master equation, let alone solve it on a classical computer. In this paper, we present a quantum algorithm for simulating the dynamics of an open quantum system. On a quantum computer, the environment can be simulated using ancilla qubits with properly chosen single-qubit frequencies and with properly designed coupling to the system qubits. The parameters used in the simulation are easily derived from the parameters of the system + environment Hamiltonian. The algorithm is designed to simulate Markovian dynamics, but it can also be used to simulate non-Markovian dynamics provided that this dynamics can be obtained by embedding the system of interest into a larger system that obeys Markovian dynamics. We estimate the resource requirements for the algorithm. In particular, we show that for sufficiently slow decoherence a single ancilla qubit could be sufficient to represent the entire environment, in principle.

Original languageEnglish
Article number062317
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Volume83
Issue number6
DOIs
Publication statusPublished - 14 Jun 2011
Externally publishedYes

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quantum computers
embedding
resources
operators
requirements
estimates
simulation
interactions

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Quantum algorithm for simulating the dynamics of an open quantum system. / Wang, Hefeng; Ashhab, Sahel; Nori, Franco.

In: Physical Review A - Atomic, Molecular, and Optical Physics, Vol. 83, No. 6, 062317, 14.06.2011.

Research output: Contribution to journalArticle

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